Gas crucible-furnace



(No Model.)

L. STILWELL.

GAS GRUOIBLE FURNACE.

No.,275,284. Patented Apr, 3,1883.

UNITED STATES PATENT QFFICE.

LYSANDER STILYVELL, OF NEWARK, NEW JERSEY.

GAS CRUCIBLE=-FURNACE.

SPECIFICATION forming part of Letters Patent No. 275,284, dated April 3,1883.

Application filed May11,188-2. (No model.)

1'0 all whom it may concern Be it known that l, LYSANDER STILWELL, acitizen of the United States, residing in the city of Newark, Essexcounty, New Jersey, have invented certain new and useful Improvements inGas Crucible-Furnaces, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.

My invention consists in an improvement in the gas crucible-furnacesheretofore constructed with acrucible heating-chamber and pipes forcombining air and gas together before combustion.

My improvements consist in the interposition between the crucibleheating-chamber and the pipes in and by which the gas and air arecombined of a mixing-chamber separate from both the heating-apartmentand the said pipes, but having communication with both in the mannerherein set forth, and arranged in relation to the heating or cruciblechamber and the said pipes, as herein shown and described.

It also consists in the construction of such mixing-chamber and itsconnections with the pipes and heating-chamber, and in the combination,with the elements already known, of a gasoline-chamber connected withthe air and gas combining pipes, and supplied with an airinlet forfeeding air to said pipes charged with the vapor of gasoline.

My invention, will be understood by reference to the annexed drawings,in which Figure 1 is acentral vertical section of a machine embodying myimprovements. Fig.2is a plan of the partition between the mixing andcombustion chambers. Fig. 3 is a plan of the plate forming the bottom ofthemixing-chamber; and Fig. 4 is a section of the gas and air tubes justbelow said plate, on line 00 w in Fig. 1, showing the connections to theseveral gastubes.

A A is the base of the machine, formed in two parts, united by flangesat a, and constituting a receptacle for gasoline and air.

13 B are pipes inserted inthe top of A, and also into a plate, 0,forming the bottom of the mixing-chamber D.

E is the floor of the melting-chamber 1, formed of fire-clay or otherrefractory material,

resting upon an iron plate, F, which has the pocket G cast in itscenter, and a depression, of cone-shape, H, upon its lower side. Theplate F forms the upper side of the mixing-chamber, and is perforated atb for the passage of the gases to the melting-chamber. The latter isformed of a cylinder, I, of fire-brick, and a cover, J, of the usualcharacter.

A wire net, K, is shown secured between the flanges a, the space Abeneath the same being filled with gasoline at pleasure by afillingtube, L.

The upper part, A, of the chamber is shown provided with an air-inlet,M, which may be connected to any suitable blast apparatus. The inlet isshown provided at its inner end with an elbow, N, by which the air isdirected toward the surface of the gasoline to aid in vaporizing it.

The pipes B are shown as six in number, arranged in a circle between thechambers A and D, and connected by nipples c to an annular pipe, 0,which receives a supply of gas from a branch, P. In the base of eachpipe is secured an air-tight nozzle, d,which tapers upward to near thetop of the pipe, but has an annular space, e, around it, as shown inFig. 4, for the influx of the gas. The latter thus enters the pipe Baround the nozzle, and rises with the air injected by the nozzle to thechamber D, where the gases are thoroughly mixed before entering themelting-chamber to be burned.

Apertures may be made through the firebrick floor for the passage of thegas without any burner-tube; but I have shown a more durable arrangementat I), which consists of metallic tubes fitted tightly to theopenings 1) in the plate F, and are provided with platinum tips f, bentso as to direct the flame toward the crucible Q. With this constructionthe'floor of the chamber is formed by packing clay or other materialsaround the pipes 0, between the pocket G in the center and a flange, F,formed around the edge of plate F for the pur pose. The flange F andpocket G are shown in plan in Fig. 2, the space between the tworepreseutin g the fire-clay floor, from which the jets or tipsfproject,as shown in the drawings.

The operation of my invention is as follows: The gas, being supplied tobranch P, feeds all forced upward through the nozzles d into the chamberD, where it is violently agitated and mixed with the inflowing'gas. Fromthence it emerges to the melting-chamber, where it is ignited at thejetsf, and where the combustion produces great heat.

With the construction shown I have melted seventy-five ounces of silverin a crucible in twelve minutes from the time of lighting the gas, andninety pennyweights of gold in another charge in fifteen minutes, whilethe devices previously known require thirty minutes to effect the sameresult.

It is obvious that certain parts of my invention may be used apart fromothers, and I do not'therefore consider the use of the gasolinechamberdependent upon the presence of the mixing-chamber, aseither may be usedwithout the other in the combination claimed therefor.

I am aware that a gas cruciblefurnace has been made with burners or jetsaround a crucible, and with a removable cup for catching the overflowfrom the crucible, and I do not therefore claim such constructions asnew; but in the said apparatus the air and gas were not mingled,except'in the tube by which the gas entered, as at B in my device, whilemy invention consists partly in interposing a mixingchamber between thetube and the point of combustion, as at D. The roof of such chamber Ihave shown formed of conical shape, projecting downward, as at H, todirect the gases to the burner-tubes b, and have utilized such depressedpart in forming a pocket, Gr, beneath the crucible. The metalaccidentally spilled into such pocket can only be removed as a buttonwhen cold, the plate I and the recess G being fixed in the machine, andnot movable.

The chamber A, in which the gasoline is stored, is shown as filled withcotton waste, or other absorbent material, R, that the vapor may becarried off by the blast of air without the priming or blowing away ofthe liquid.-

The screen K servesto keep the waste in place, especially when theapparatus is moved about; but would not be needed were any heavierabsorbent material used than the cotton.

It will be seen from the above that theprominent feature of theconstruction is the location of the injector-tubes B d between an air orgasoline vessel and a mixingchamber, and the arrangement of the latterbetween the tubes B d and the crucible-chamber I. The respect ivechambers may therefore, if preferred, be formed in one connectedcasting, and the air and gas tubes be led inside by other arrangementsthan those shown. The piping-connections shown herein are, however, verycheap and effective, being formed of ordinary gasfitt-ings united byright and left hand threads, and admit of ready examination and removalfor repairs.

The tubes B are each provided with a branch at the middle to receive thegas-nipple c, a nipple below the branch having the air-nozzles solderedtherein, and a nipple or pipe above the branch to guide the gas upward,with the air, into the mixing-chamber. Each tube B is screwed into thecastings A and O, and the nipples c are then inserted to connect eachtube with the annular supply-pipe O.

The machine may be constructed with a single pipe Bin the center of thechambers A and I), or with any number of pipes B, as preferred; but thechamber would be provided in any case with a number of outlets, as at b,and the combustion-chamber I used for heating any other object than acrucible, as may be desired.

I am aware that a hollow dome located beneath the crucible chamber hasbeen patented in No. 227,852, of May 18, 1882, for collecting andigniting the air and gas previously mingled in the mixing-tubes, and Ido not therefore claim such an intermediate chamber broad- 1y, but onlywhen used as a mixing-chamber alone. In the said patent the flameis saidto strike the-bottom of the crucible and pass up into the furnace, whilein my construction no flame is produced below the crucible; but the gasand air, after mingling, as described, in the chamber beneath the same,are conducted through jet-tubes and ignited first in thecrucible-chamber itself.

For certain purposes it may be desirable to use a portion of myconstruction without employing all the parts described in onecombination, and I have therefore made separate claims, as is usual, tothe combinations I regard as new. I do not, however, claim myinventionin combination with any other furnace than the one described, in which achamber expressly adapted to receive a crucible is implied, as I amaware that many gas-furnaces for other purposes have been used, and thatmy invention is particularly adapted for the application of a gas-flameto a crucible in the manner herein described.

If desired, the burners may be arranged in other relations to thechamber I, and may enter the same upon one side, or otherwise, aspreferred.

I am aware that many constructions have been devised for carburizin gair to be burned, and I do not therefore claim such an invention. I amaware that an apparatus for can burizing air for various kinds offurnaces is shown in English Patent No. 2,214 of 1873. I thereforedisclaim said English patent, as well as the carburetor A, or anyequivalent therefor, when used apart from the specific combinationclaimed herein; but I am not aware of any crucible-furnace in which airis passed over gasoline to absorb the vapor and then, mixed with a fixedgas supplied by jets in a nozzle, as herein shown and described.

I am aware that a mixing apparatnsis shown in English Patent No. 652 of1867, for mingling and propelling a mixture of air and gas by means of asteam-jet, and I therefore disclaim such English patent, my inventionconsisting in the arrangement herein described and shown.

I hereby reserve the right to make subsequent application for the methodand process herein shown and described; also for the construction andcombination of my apparatus, not herein specifically claimed ordisclaimed.

Having thus described the nature of my invention, I claim the same asfollows:

1. The combination, with the combustionchamber I and mixing-chamber D,provided with a gas and air supply pipe, of the intermediate plate, F,provided with flange F, the pocket G, having the conical projection H,and tubes 1), connecting said mixing-chamber with the chamber I,substantially as shown and specified.

2. The combination, with air and gas pipes constructed substantially asdescribed, of the mixin g-chamber D, formed of the plate 0, having thetubes B secured to it, and of the plate F, having the recess orstationary pocket G formed in its upper side, the pocket beingsurrounded with the refractory floor-packing E, and the plate beingprovided with the burner-tnbes I), penetrating the plate F, andrefractory filling E, substantially as shown and described.

3. In a crucible-furnace, the combination of chamber I, chamber D, andcommunicating tubes b, tubes B, having nozzles (Z located therein, andthe gasoline-chamber A, provided with airinlet M, substantially asherein set forth.

4. In a crucible heating-furnace, a combustion-chamber, I. supportedupon a closed base having pocket G and gas-conveying tubes 1), incombination with the mixing-chamber D and gas-chamber A, connected bymeans of pipes B, having nozzles d, the parts being arranged andorganized substantially as specified.

5. The combination of a crucible-furnace with the chamber A, providedwith a wire screen, K, and air-inlet pipe M, as shown, in combinationwith the chamber D, the two chambers being connected by the pipes B,havingnozzles d, the same being provided with a gas-supply pipe, 0, andconnecting means substantially as shown, and for the purpose set forth.

In testimony whereofI have hereunto set my hand in the presence ot' twosubscribing witnesses.

LYSANDER STILWELL.

Witnesses:

WM. F. D. CRANE, WALTER M. OoNGER, Jr.

